PSTN / Phone Calls API not enabled – HTTP 404 on /v1/phone-calls

Support Help
1

Hi Retell Team,

Our workspace has:

  • Active Pay-As-You-Go billing
  • Valid API keys
  • Agents created and tested

However, Phone / PSTN features are not visible in the dashboard.
POST requests to /v1/phone-calls return:

HTTP 404 – Cannot POST /v1/phone-calls

We are integrating Retell with Asterisk AGI (Phase-2) and are blocked
due to PSTN not being enabled at the account level.

Workspace: PAK SAIBAN
Use case: Asterisk AGI → Retell Voice → PSTN

Kindly enable PSTN / Phone Calls for our workspace.

Thanks

2

Based on the available sources, your 404 error is likely due to an incorrect API endpoint. The correct endpoint for creating phone calls is /v2/create-phone-call, not /v1/phone-calls(1).

For your Asterisk AGI integration with Retell, you should use the Dial to SIP URI method since you have a custom telephony setup(2). The Retell SIP server URI is sip:sip.retellai.com(2).

Key configuration details:

Transport methods supported(2):

  • TCP (Recommended): sip:sip.retellai.com;transport=tcp
  • UDP: sip:sip.retellai.com;transport=udp
  • TLS: sip:sip.retellai.com;transport=tls

IP blocks for traffic whitelisting(2):

  • 18.98.16.120/30 (All regions)
  • 143.223.88.0/21 (certain United States traffic)
  • 161.115.160.0/19 (certain United States traffic)

For the 404 error specifically:

Common causes include(1):

  1. Phone number not properly configured - your from_number must be purchased/configured through Retell AI
  2. Incorrect parameter names - use override_agent_id instead of agent_id
  3. Missing agent binding - the phone number should have an outbound_agent_id configured

Required request format:

{
  "from_number": "+16504144521",
  "to_number": "your_target_number",
  "override_agent_id": "agent_71724df7636716ceb3a7e244c8",
  "retell_llm_dynamic_variables": {
    "name": "Sarah"
  }
}

(1)

Regarding PSTN enablement - based on a similar case, inbound PSTN calling requires workspace-level permissions that may need to be enabled by Retell support(3).

For direct assistance with workspace-level PSTN enablement:

3

Hello @paksaaibaan

  • To make phone calls, this is the API you need to use: https://api.retellai.com/v2/create-phone-call

  • You should be able to see a ‘Phone Numbers’ tab on your account, which is typically enabled by default for everyone. If you can’t see it, please share a screenshot of what you can see.

4

To create outbound phone calls with Retell AI, you’ll use the Create Phone Call API endpoint.(1)

API Endpoint:
POST /v2/create-phone-call(1)

Requirements:

  • A phone number purchased from Retell or imported to Retell (from_number)(1)
  • The destination number in E.164 format (to_number)(1)
  • Your API key for authorization(1)

Example Code:

import Retell from 'retell-sdk';

const client = new Retell({
 apiKey: 'YOUR_RETELL_API_KEY',
});

const phoneCallResponse = await client.call.createPhoneCall({
 from_number: '+14157774444',
 to_number: '+12137774445',
});

console.log(phoneCallResponse.agent_id);

(1)

Key Parameters:

  • from_number: Your Retell number in E.164 format (e.g., "+14157774444")(1)
  • to_number: The destination number in E.164 format (e.g., "+12137774445")(1)
  • override_agent_id: The agent ID to handle this call (e.g., "oBeDLoLOeuAbiuaMFXRtDOLriTJ5tSxD")(1)

Phone Numbers Tab:
The Phone Numbers tab should be visible in your dashboard by default.(2) If you’re not seeing it, there may be a configuration issue with your account.

Common Issues:

  • Ensure your from_number includes the “+” prefix in E.164 format(1)
  • Verify your phone number is properly connected in the dashboard(2)
  • Check that your API key is correct(2)
  • Make sure there are no extra white spaces in your phone number configuration(2)